[tipoboy]

you would add our plugin and use the hook location

load_show_variables

then your plugin would be

if (is_member_of(vB::$vbulletin->userinfo, 6, 7, 2, 5))
{
    $show['xxxxx'] = true;
}

changing the usergroups the the usergroups you wish to see the tab and changing the 'xxxxx' in the code to your unique forum permission name for use when adding your tab

HTH